Some of the most dreadful pandemics in the history of mankind result from the rapid spread of infectious diseases caused by virulent pathogenic organisms. These disease states are often accompanied by other opportunistic infections (viral, protozoal, bacterial or parasitic) and/or diseases due to the compromised immune system of infected patients.
There is new evidence that new epidemics are emerging throughout the industrialized, developing and transitional countries of the world.
Today, the rates of reported cases of diseases are increasing in exponential proportions and clinical treatments currently available represent only marginal improvements in the management of health care in this area. The rapid increase in the number of infectious diseases ranges from alarming to out of control. Unless improved treatments are found the future outlook for the state of the world's health is dismal. The scientific community throughout the world is mindful of the long-felt need for effective ways to
(1) substantially reduce, eliminate, neutralize and/or kill virulent pathogenic organisms or agents,
(2) inhibit the proliferation of rapidly replicating abnormal (infected or altered) cells caused by pathogenic organisms, or agents such as a virus, bacteria, fungus, venom, pollen, protozoal, and mixtures thereof and
(3) identify effective vaccines, preventive (prophylactic) and therapeutic treatments for patients, including humans. In response to the need to alleviate suffering and provide comfort to human life, the scientific community is searching for effective means to inhibit the growth of rapidly proliferating abnormal mammalian cells caused by pathogenic organisms within the genus Rickettsia, such as O. tsutsugamushi alone and/or in combination with others.
Scrub typhus, also referred to as chigger-borne rickettsiosis, mite-borne typhus, Japanese river fever, tropical or rural typhus or tsutsugamushi disease is an acute, febrile disease caused by infection with Orientia (formerly Rickettsia) tsutsugamushi. It accounts for up to 23% of all febrile episodes in endemic areas of the Asia-Pacific region (5). The disease is characterized by a rise in body temperature, skin rash and severe headaches. This disease may affect the nervous system, with clinical manifestations such as delirium, stupor and muscle fibrillation. The death rate varies from 1 to 60% depending on the geographical regions. Scrub typhus, transmitted to mammals (including humans and cattle) through the bite of tiny trobiculid mites (arthropods) is particularly high is South-East Asia, Korea, Russia, Australia, China, Japan and India. The incidence of disease has increased in some countries during the past several years (6).
The causative organism is transmitted to human through the bite of tiny trobiculid mites. The organisms are found throughout the mite's body, but the highest number occurs in the salivary glands. When the mites feeds on mammals, including cattle, rodents or humans, the disease causing organisms are transmitted from the mite to the invertebrate host (subject). Scrub typhus infections are usually found in people engaged in activities that bring them inadvertently in contact with mite-infested habitats or any invertebrate host-carrier of these anthropods. These hosts may include somesticated, non-domesticated or farm animals, such as cattle or rodents. These hosts may be carrying mites which have not begun to feed on them. In this case, when the host is cattle, the live mites can be transferred from cattle to people. Individuals particularly susceptible include butchers, meatworkers, animal-farm workers and others engaged in outdoor activities. These persons could be infected by coming into contact with these mite-carrying animals. Additionally, rodents are capable of carrying and spreading infected mites to people in populated areas.
Only larval Leptotrombidium mites feed on vertebrate hosts. The larval mites acquire O. tsutsugamushi through their female parent. This type of pathogen reception is called “transovarial transmission.”
Once transmitted to the host, the organism incubates for about 10 to 12 days. From 5 to 8 days after infection, a dull read rash may appear all over the body, especially on the trunk. Mortality ranges from 1 to 60%. Death either occurs as a direct result of the disease, or from secondary effects, such as bacterial pneumonia, encephalitis, or circulatory failure. If death occurs, it is usually by the end of the second week of infection. Despite these tragic statistics, many people around the world do not understand or believe how deadly scrub typhus can be until it is too late. Unfortunately, too many people are unwittingly dancing with death.